While it may seem like Linux-only projects are betraying their loyal base by developing Windows or OSX versions, I would argue that cross-platform development is actually better for Linux as a whole, better for individual software projects and their developers, and ultimately better for Linux users.

AIUI the only functionality lost to the BSDs was automounting of external drives. This is because HAL is deprecated - it would be unrealistic to expect the (small) Xfce team to maintain HAL just for backward compatibility.

If automounting cannot be lived without, use 4.6, and hope someone provides a udev implementation on BSD.